Hi. There seem to be multiple topics on this Forum referring to the same issue: iPad 2 with SIM installes suddenly seems to 'loose' the SIM and reportsmin the top left corner: No SIM. A popup screen appears: No SIM card installed.
I have the same issue, not resolved yet. What I have seen/tried so far:
- after hard-shutdown the problem is gone. Then after a while it comes back
- same story when enabling Flight Mode. After a while the issue comes back.
- i have replace the SIM card. When turned on it all worked fine, after 30 mins I got the same error.
- it does not aooear to be a hardware problem, because then it would be more consistent
- it also does not aopear a software problem
- i have phone AppleCare. They did not know this problem. They suggested me to do a total system reset.
To be continued...
I have performed a system reset: Settings > General > Reset > Reset All Settings. All data remains on the iPad, but just the settings are reset. It did not resolve the issue; after 10 mins the No Sim error appeared again.
So then I performed a full reset: Settings > General > Reset > Reset all content and Settings. After this I added the SIM card and since then it has worked fine. The data/content was place back after connecting it to iTunes. When asked 'do you want to restor existing iPad' i decided to build a new one.
Hopefully the problem is now resolved...
I've the very same problem as you, this started just after upgrading my iPad 2 to iOS5 and now it's happening more and more often.
I tried to switch-off, reset, restore, re-insert the SIM multiple times but nothing fixed the issue for more than a couple of hours. That's really annoying and lot of people seem to have this issue :((
I don't know what else to try... I'm afraid than even sending the iPad for repair will only be a waste of time!
Update: I got a replacement SIM from my carrier but the problem persisted, so I took my iPad to Apple service and they replaced it with a new one.
Now I'm happily connecting to my 3G network again
My suggestion for people experiencing the same issue is to try a "minimum troubleshooting" i.e. restore your iPad and the like but do not waste much time before going to Apple service if the problem continues.